<!DOCTYPE html>
<html ng-app='test'>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script src="angular.js"></script>
    <script type="text/javascript">
      let mod_a =angular.module('a',[]);

      mod_a.controller('test_a',function($scope){
          $scope.a=12;
      });

      let mod_b=angular.module('b',[]);
      mod_b.controller('test_b',function($scope){
        $scope.b=5;
      });
      let mod=angular.module('test',['a','b']);
    </script>
  </head>
  <body ng-controller='test_a'>
    {{a}}
  </body>
</html>
